Objective To investigate and identify the cause of food poisoning of Field Snail.Methods Using the methods of epidemiological investigation and laboratory tests, 35 samples, including the anus swabs from the food poisoned patient and the Field Snail processor and seller, the swabs from the environment in which the Field Snail was processed and sold and the Field Snails leftover were analyzed, according to the national standard methods. Results The cause of the poissing was that the Field Snails had not been thoroughly cleaned and properly cooked. Among those samples, Enteropathogenic E.coli(EPEC) was detected from 2 anus swabs,1 leftover Field Snail and 1 swab from Field snail processing and selling environment. Conclusion The food poisoning was caused by eating Field Snails polluted by Enteropathogenic E.coli(EPEC).